1. Field of the Invention
The present invention relates to a device for filling and closing pressurized-steam containers of the type comprising: a closing member operatively and sealingly engaged to a filler exhibited by the container: an operating cap integral with the closing member and operable in rotation so as to bring the closing member from a sealing position in which said filler is hermetically closed to the surrounding environment to a supply position in which the filler is in communication with the surrounding environment.
In more detail, the invention relates to the field of safety devices associated with fillers in steam boilers of the type used, for example, for supplying steam irons and/or washing apparatus for domestic or industrial use with water.
2. Prior Art
It is known that boilers for steam production of the above type are usually provided with a filler enabling the water required for producing steam to be introduced thereinto. A closing member is engaged by screwing to said filler. The closing member is provided with an opening cap adapted to enable the closing member to be screwed down and unscrewed manually. In addition, provision is generally also made for means adapted to eliminate or at least reduce the risk that the user may suffer from severe burns, should he/she imprudently try to remove the closing member when there is still pressurized steam in the boiler.
To this end, in the simplest construction solutions at least one vent canalization is formed in the closing member and/or the filler. Said canalization, as soon as the plug is loosened from the tightened condition, causes possible steam still present in the boiler to escape therethrough in small amounts, so that the user is visually warned about the presence of pressure in the boiler before completely removing the closing member. However, since said canalization must necessarily have a very narrow passage section, it can be easily obstructed by lime scale or other impurities, which results in its impossibility of performing the intended functions.
According to other technical solutions, the closing member is combined with a visual signaller consisting for example of a pin that, upon command of a diaphragm communicating with the inside of the boiler, protrudes from the operating cap when pressure is present in the boiler, in order to signal said pressure presence.
However, the presence of said signaller does not prevent the user from removing the closing member from the filler, due to unawareness or carelessness or perhaps because the signalling device is out of order.
There are solutions too in which a pin is provided to be associated with the boiler, which pin, in the presence of pressure, is pushed into a corresponding housing formed in the operating cap of the closing member. The engagement of the pin is said housing prevents the closing member from being removed in the presence of pressure. On the other hand, such a device has been found to be of difficult construction because it is necessary to ensure that, under tightening conditions of the closing member, said housing be perfectly aligned with the pin.
In another known construction solution the operating cap is rotatably engaged to the closing member, and can be clamped thereto by a coupling mechanism controlled by a diagram responsive to the inner boiler pressure. In greater detail, this diaphragm acts in such a manner that the operating cap rotates freely relative to the closing member in the presence of pressure in the boiler, thereby preventing the closing member from being removed therefrom. When the inner boiler pressure goes below a predetermined value, the coupling device acted upon by the diaphragm makes the operating cap integral in rotation with the closing member. Under this situation, the closing member can be removed and the boiler can be filled.
After the above description it is apparent that, irrespective of all measures adopted for safety purposes, all closing devices presently in use need the closing member to be completely removed for carrying out the boiler filling. Thus, frequent filling operations are particularly troublesome taking also into account the fact that their execution requires the aid of accessories such as funnels or the like in order to facilitate the introduction of water into the boiler.
In addition since the closing member is made as an element physically independent of the boiler, it can be easily damaged, if it is for example dropped, and maybe even inadvertently lost by the user.
It is also and above all pointed out that none of the known solutions is capable of preventing the closing member from being removed from the filler and therefore eliminating the risks of burns, should the provided safety devices be out of order.